The optic cup is the white, cup-like area in the center of the optic disc.
The ratio of the size of the optic cup to the optic disc (or cup-to-disc ratio) is measured to diagnose glaucoma. Normal cup to disc ratio is 0.3 If it is more than it suggests glaucoma.
Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine cell) → Retina ganglion cell (Midget cell, Parasol cell, Bistratified cell, Giant retina ganglion cells, Photosensitive ganglion cell) → Diencephalon: P cell, M cell, K cell
proc, drug (S1A/1E/1F/1L)